Among the most contentious issues then facing Harvard was how to expand beyond the confines of Cambridge. The university had been buying up property across the Charles River in the Boston neighborhood of Allston. When Mr. Summers’s predecessor, Neil L. Rudenstine, suggested that the law school move, the law faculty responded by voting against it, 37 to 1.

But when Mr. Summers was installed as president in 2001, he put the Allston move back on the table. With the faculty up in arms, the longtime law school dean, Robert C. Clark, asked Ms. Kagan to head a study committee; he thought she had the potential to succeed him as dean and wanted to give her a leadership role. Ms. Kagan, who had just been granted tenure, would be wading into perhaps the most fractious issue at the university.

She seemed to have an instinctive feel for how to build a case that would work with Mr. Summers. “Her approach was to give a rational basis, instead of just an emotional one, for the faculty’s reaction,” Professor Clark said.

She hired a consultant, and persuaded the university to foot the bill, producing a 101-page strategic plan that considered everything from future growth to dormitory space to the intellectual benefits of remaining near the arts and sciences buildings. She made no explicit recommendation, but the study strongly suggested that Allston was far better suited to the biomedical sciences than the law school. The plan was soon dead, and Ms. Kagan gained folk hero status.